Orconectes validus

Orconectes validus (Faxon)

Cambarus immunis.—Hagen, 1870:73 [in part].

Cambarus validus Faxon, 1914:382, 383 [in part], 421, pi. VII: figs. 4, 8; pi. XIII: fig. 1—Ortmann, 1931:91, 93, 94 [in part].—Hobbs, 1949:19—Bouchard, 1976a:582.

Faxonius validus.—Creaser, 1933a:3 [by implication]; 1962:2 [by implication].

Faxonius (Faxonius) validus.—Creaser, 1933b:21 [by implication].

Orconectes validus.—Hobbs, 1942a:352 [by implication]; 1949: 23; 1968:K14, K32, fig. 31f; 1972:90, 149, fig. 72b; 1974: 42, fig. 168.—Bouchard, 1976a:563, 574, 576, 582; 1976b: 14.—Bouchard and Bouchard, 1976:466, 467, fig. 2c, d.—Fitzpatrick, 1976:56.

Orconectes (Orconectes) validus.—Hobbs, 1942b:154 [by implication]; 1959:895.

DIAGNOSIS.—Body and eyes with pigment. Rostrum lacking carina, usually with marginal tubercles, occasionally with distinct spines, and infrequently tapering to apex without distinct angle at base of acumen. Areola obliterated (along part of length) to 7.4 times as long as wide and comprising 26.5 to 34.2 percent of entire length of carapace (36.3 to 43.9 percent of postorbital carapace length), with 0 to 2 punctations across narrowest part. Cervical spine present, sometimes reduced to tubercle. Suborbital angle obsolete. Postorbital ridge well developed, with or without small apical tubercle. Antennal scale approximately 2.5 times as long as broad, widest at or slightly distal to midlength. Chela with palm inflated, bearing mesial row of about 8 subsquamous tubercles, and with irregular rows of tubercles subtending it; fingers gaping; fixed finger with proximal half of opposable margin studded with dense tufts of plumose setae. Hook on ischium of third pereiopod. First pleopod of first form male without angular shoulder on cephalic surface, with distal three-fifths inclined caudally; terminal elements curved throughout and usually reaching base of second pereiopod when abdomen flexed; pleopod length divisible into carapace length 2.6 to 3.6 (average 3.2) times; terminal elements slender and subparallel: central projection, constituting 26.7 to 38.6 percent of total mesial length of appendage, bladelike, tapering from base and not extending so far caudally as mesial process; mesial process expanded distally and with shallow groove extending from near midlength of cephalic surface to caudally directed tip of process. Annulus ventralis as figured. First pleopod of female extending cephalically to midlength of annulus when abdomen flexed.

TOPOTYPIC MALE, FORM I.—Body and eyes pigmented. Cephalothorax (Figure 3a, i) subcylindrical in section; abdomen narrower than carapace (15.4 and 18.5 mm), width of latter greater than depth at caudodorsal margin of cervical groove (18.5 and 14.7 mm). Areola narrow, 27.8 times as long as wide with single punctation in narrowest part. Length of areola 31.8 percent of entire length of carapace (41.1 percent of postorbital carapace length). Rostrum with slightly thickened, elevated borders converging to base of acumen, and bearing corneous marginal tubercles; acumen reaching slightly beyond midlength of ultimate podomere of antennular peduncle and terminating in corneous, acute, upturned tip; upper surface concave and punctate. Subrostral ridge weakly developed and evident in dorsal aspect only in caudalmost portion. Postorbital ridge strong, grooved laterally, and with subacute, corneous apical tubercle. Suborbital angle virtually obsolete. Cervical spine moderately heavy, short (left member bispinous), and only slightly larger than branchiostegal spine. Carapace punctate dorsally, punctations crowded and rather deep in cephalic gastric region; strongly granulate laterally except immediately ventral to cervical spines and near caudal extremity. Abdomen and carapace subequal in length (35.2 and 34.9 mm). Pleura of moderate length, rounded ventrally. Cephalic section of telson with 2 spines in each caudolateral corner. Proximal podomere of uropod with short, corneous spine on each lobe; mesial ramus with moderately well–developed dorsomedian keel terminating in small premarginal spine.

Cephalic lobe of epistome (Figure 3g) distinctly broader than long with weak cephalomedian prominence and with cephalolateral borders undulating; main body of epistome with distinct fovea situated at cephalic end of median groove; epistomal zygoma broadly arched. Basal segment of antennule with dense band of long plumose setae on mesial surface partially obscuring ventral spine located near midlength. Antennal peduncle with spine on lateral surface of basis and minute one on ischium. Antenna broken, but in other specimens reaching slightly beyond midlength of abdomen. Antennal scale (Figure 3l) about 2.4 times as long as broad, greatest width approximately at midlength; thickened lateral area with apical spine reaching level of tip of rostrum. Third maxilliped with almost entire ventral surface of ischium and peduncle of exopodite bearing dense mat of plumose setae.

Chela (Figure 3j) about 2.3 times as long as wide; palm inflated, its mesial margin with mesial row of 8 tubercles, subtended dorsally and ventrally by irregular rows of 8 and 6, respectively; remainder of palm punctate except for prominent tubercle ventrally opposite base of dactyl; lateral margin of chela subcostate almost from base to near midlength of finger, costa rounded laterally and polished. Fixed finger strongly arched laterally with opposable surface bearing, among setae, row of 11 tubercles along proximal three–fourths, fifth from base largest and all knoblike; large tubercle at lower level between ninth and tenth tubercles from base; minute denticles extending distally from between seventh and eighth tubercles to corneous tip of finger; tubercles along proximal half of finger flanked by conspicuous tufts of plumose setae; dorsal and ventral surfaces of finger with broad, low submedian ridge flanked by setiferous punctations; secondary ridge present between median ridge and setal tufts. Dactyl with opposable margin concave basally and bearing row of 11 tubercles decreasing in size distally and extending along basal three–fourths of finger; minute denticles extending from fifth tubercle from base to corneous tip of finger interrupted by more distal tubercles; dorsal and ventral surfaces of finger with low submedian longitudinal ridge flanked by setiferous punctations; secondary ridge situated between submedian ridge and opposable margin; mesial surface of dactyl tuberculate in proximal three–fourths and punctate distally.

Carpus 1.6 times as long as broad with deep oblique furrow on upper surface; mesial surface bearing prominent spine near midlength and 2 tubercles proximally; dorsal distomesial margin with low tubercle; ventrodistal margin with sub–median corneous–tipped tubercle and another on ventrolateral condyle; ventromesial surface with 2 rounded tubercles.

Merus with 2 subdistal spines dorsally; mesial and lateral surfaces punctate; ventral surface with lateral row of 6 tubercles (third and sixth from base spikelike) and mesial row of 11, none of which spikelike; also lateral extremity with spine. Ischium with row of 3 small tubercles, proximal–most largest.

Mesial surface of carpus and propodus of second pereiopod not densely setose.

Ischium of third pereiopod with simple hook extending proximally over distal extremity of basis; hook not opposed by tubercle on basis.

First pleopods (Figures 3b,f,k) symmetrical, extending cephalically to second pereiopod when abdomen flexed. (See “Diagnosis” for description.)

TOPOTYPIC FEMALE.—Differing from male, form I, in following respects: abdomen and cephalothorax subequal in width (14.9 and 14.8 mm); areola only moderately narrow, 13.9 times as long as wide; marginal tubercles of rostrum minute; acumen reaching level of distal end of antennular peduncle; length of chela only 71 percent that of carapace, with inflation of palm and curvature of fixed finger less pronounced; mesial margin of palm with mesial row of 9 tubercles subtended by irregular rows of 6 dorsally and 4 ventrally; fixed finger with 7 tubercles along proximal half of opposable margin, large one at lower level slightly distal to midlength, and denticles beginning at midlength and extending almost to tip of finger; opposable margin of dactyl with 8 tubercles along proximal three-fifths; ridges on dorsal and ventral surfaces of fingers slightly stronger than in male; mesial surface of carpus with additional 3 small tubercles dorsal to those present on male. (See Table 2.)

Annulus ventralis (Figure 3d) moderately deeply embedded in sternum, firmly fused with latter cephalically; cephalic portion with anteromedian trough flaring between and beneath oblique cephalolateral walls; digitiform tongue present, and wall of annulus caudal to tip of tongue strongly elevated and thickened; sinus originating under cephalosinistral wall slightly cephalic to midlength, following contour of tilted, reversed S, and ending on caudomedian wall of annulus. Postannular plate approximately 3 times as broad as long and about three–fourths width of annulus. First pleopod extending cephalically slightly beyond midlength of annulus when abdomen flexed.

TOPOTYPIC MALE, FORM II.—Differing from male, form I, in following respects: cephalic lobe of epistome trapezoidal with no cephalomedian projection; mesial margin of palm with mesial row of 8 tubercles, subtended by 7 dorsally and irregular row of about 4 ventrally; fixed finger with 14 tubercles along opposable margin, with 1 ventral to row; dactyl with 13 tubercles along opposable margin; hooks on ischia reduced and not overreaching distal extremity of basis. (See Table 2.)

First pleopod (Figure 3c,e) differing from that of first form male chiefly in decidedly shorter terminal elements, in the absence of corneous texture of central projection, in shallower cleft between elements, and in absence of groove on mesial process.

COLOR

Orconectes (Gremicambarus) validus (Faxon)

Cambarus validus Faxon, 1914:382, pl. 7: figs. 3, 4, 8, pl. 13: fig. 1.

Faxonius validus.—Creaser, 1933a:3 [by implication]; 1962:2 [by implication].

Faxonius (Faxonius) validus.—Creaser, 1933b:21 [by implication].

Orconectes validus.—Hobbs, 1942a:352 [by implication]; 1974b:42, fig. 168.—Fitzpatrick, 1963:61 [by implication].—Cooper and Hobbs, 1980:8, figs. 2b, 3–6.

Orconectes (Orconectes) validus.—Hobbs, 1942b: 154 [by implication].

Cambarus (Faxonius) validus.—Bouchard, 1972b:103.

Orconectes (Gremicambarus) validus.—Fitzpatrick, 1987a:54.

TYPE.—Holotype, MCZ 301 (male I).

TYPE LOCALITY.—Huntsville, Madison County, Alabama.

RANGE.—Tennessee and Black Warrior river systems in northern Alabama and southern Tennessee.

HABITAT.—Streams.

Orconectes validus (Faxon)

Cambarus validus Faxon, 1914:382, pl. 7: figs. 3, 4, 8; pl. 13: fig. 1.

Faxonius validus—Creaser, 1933a:3 [by implication]; 1962:2 [by implication].

Faxonius (Faxonius) validus.—Creascr, 1933b:21 [by implication].

Cambarus validus Faxonianus.—Fleming, 1938:303 [not validus Faxon; see O. rhoadesi].

Orconectes validus.—Hobbs, 1942a:352 [by implication].—Fitzpatrick, 1963:61 [by implication].

Orconectes (Orconectes) validus.—Hobbs, 1942b: 154 [by implication].

TYPE.—Holotype, MCZ 301 ( I).

TYPE-LOCALITY.—Huntsville, Madison County, Alabama.

RANGE.—Tennessee drainage below Walden Gorge in Alabama and southern Tennessee, and upper Black Warrior and Tombigbee drainages in Alabama.

HABITAT.—Streams.